


One Chicago HeadCanons

by buddie_brettsey



Category: Chicago Fire, Chicago Med, Chicago PD (TV), One Chicago
Genre: Angst, Canonical Character Death, Childhood, Established Relationship, Fluff, Fluff and Angst, Headcanon, High School, Implied/Referenced Child Abuse, Multi
Language: English
Status: In-Progress
Published: 2021-01-04
Updated: 2021-01-05
Packaged: 2021-03-14 09:27:29
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 12
Words: 3,346
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28543299
Author URL: https://archiveofourown.org/users/buddie_brettsey/pseuds/buddie_brettsey
Summary: A ongoing collection of Chicago Fire, PD and Med themed head canons originally posted on my tumblr @buddie-brettsey. You can also send me requests there ☺️
Relationships: Jay Halstead & Hailey Upton, Jay Halstead/Hailey Upton, Kim Burgess/Adam Ruzek, Stella Kidd/Kelly Severide, Sylvie Brett & Matthew Casey, Sylvie Brett/Matthew Casey
Comments: 2
Kudos: 23





	1. Fluffy Upstead Headcanons

**Summary for the Chapter:**

> “Request: Asked by anon, Got any upstead headcanons? I made the mistake of going onto Twitter and now I need some positivity.“

•Once they get together, it doesn’t take long for them to move in together. Took too long to confess their feelings, so now they aren’t wasting anymore time being apart

•Hailey then introduces Jay to the world of throw pillows, fuzzy blankets and sweet scented candles. Jay quickly becomes obsessed and starts sneaking off to Target to buy more

•Jay really try's hard to learn how to cook just for Hails. He isn’t the best but she appreciates the gesture

•Hailey likes painting to clear her head after a bad case. Jay clears a corner by the window for her to paint by. Jay insists on hanging each piece on the walls (they’re running out of room but he doesn’t care) 

•As previously discussed, Hailey kills the spiders. Jay just high pitched screams 

•Adam, Kim and Kevin decide the Upstead apartment is the place to be and always come and crash their nights but they don’t mind. Kim makes homemade snacks so they’re all happy

•Speaking of, seeing how happy Jay and Hailey are makes Kim and Adam give their relationship another go

•Voight is the one who walks Hailey down the aisle. •Jay even asked Voight before he proposed because Voight is the one who knows them best and it makes that old hardass shed a tear


	2. Matt Casey’s Childhood Headcanons

**Summary for the Chapter:**

> “Request: Anon asked, Headcanons about Matt Casey’s childhood?”

•Casey decided to become a firefighter around age 10 after his neighbors house burnt down and he stayed up all night staring out of his bedroom window watching the firefighters run in and out. 

•He truly couldn’t get enough of seeing the lights and action after that

•Christie would take him to the academy to watch the cadets run drills from across the street when they had time 

•His dad was obviously abusive to his mom so he’d stay out late to avoid the yelling. 

•He ran around a lot with neighborhood kids even though he didn’t like them much, just enjoyed being out of the house. 

•His mother was very protective of him all his life. More so than his sister. Matt is the baby after all.

•Matt played football as soon (bitty league) as he could until he was done with high school. He turned down a college scholarship for the Fire Academy. 

•His dad was a contractor, so he spent weekends helping him. Hence his construction company now.


	3. Stella, Sylvie and Emily being best friends

**Summary for the Chapter:**

> "Request: Anon asked, Ik foster isn't on the show anymore but some headcannons about her, Brett and stella doing just girl bonding activities"

•It’s might’ve taken Sylvie a bit to warm up to Emily but the three of those girls are inseparable now!

•Sylvie loves spin classes sure, but the reason she loves spin is because she loves baking just as much

•Sylvie signs the girls up for cake decorating classes and they bring the treats they made that day into Molly’s that night to share

•It’s supposed to be a girl bonding thing but it actually becomes the bar’s favorite time of the week

•One night they bring a cake decorated like a firetruck and Mouch decides it’s needs photographed and hung in Molly’s

•One day Stella finds out Sylvie and Emily can’t tell the difference between Chardonnay and Sauvignon Blanc which obviously prompts Stella to sign them up for a wine tasting class

•Emily doesn’t care much for actual classes, much too chill for that. Her favorite activities are going to cafes to try the new trendy coffee or going to Navy Pier to for fresh air

•The cafes happen to always have cute baristas so Stella and Sylvie watch as Emily always leaves with at least one new phone number

•During hockey season they head to Indiana to see their favorite team play and are always welcomed with open arms. (Sylvie learned what a “sin-bin” is and is very proud of herself)

•These 3 are inseparable, the rest of 51 are jealous of how close they are but will never say anything. Too afraid they’ll stop bringing treats ☺️


	4. Hailey Upton in college

**Summary for the Chapter:**

> ''Request: Anon asked, Headcannons about hailey in college?"

•Hailey's mother is the one who insists on her going to college whereas Hailey wanted to work a few odd jobs then go to the police academy as soon as she turned 21

•She gets a Bachelor’s degree in Criminology. Minor in Political Science.

•We know Hailey as being a total badass and kind of loud when she wants to be but in college she’s the opposite

•She's quiet but tough. A guy will come up to ask her out and she gives him a look that says “walk away” without actually saying the words

•Nothing and I mean nothing will mess up her chances of getting into the academy (again she doesn’t even want to be in college in the first place)

•That means no parties. No drinking, no drugs. No loud friends. She keeps to herself.

•Until one day she’s meets a boy as quiet and as passionate as she is

•She dates a boy from her victimology class for a year, he’s her first love. They start innocently planning a cute future together, she'll go to the CPD academy. He'll go to the FBI. •Those plans go out the window when one day he gets mugged and killed while walking back to his dorm after class

•His death only fuels her desire to become a detective one day, wanting to prevent senseless deaths like her boyfriends

•It’s only in the academy and after his death does she realize her true voice and power

•She still hasn't told Jay or any of the team, too afraid they won't let her work on certain cases but it eventually comes out


	5. Matt Casey in Highschool

**Summary for the Chapter:**

> "Request: foreverdawsey asked, Would love to hear more Casey headcanons! 💗 personally i headcanon he was always the one picked to lead group projects, sports teams etc, even when he wasn’t trying, just because he’s always been a natural leader (with a huge heart)"

•You think Matthew Casey’s first political run was for alderman? No his first was actually for head of student council in 11th grade.

•He’s that kid that you hate because he’s good at everything

•Captain of Truck 81? Do you mean Captain of the 2001 State Champion Football team?

•Star quarterback for the varsity team but at halftime he runs to join the marching band to play drums on the same field he was just making touchdowns on

•All the girls want him and all the boys want to be him

•He looks very put together but no one realizes how bad things are at home. No one knows the reason he’s spreading himself thin with all these extracurricular activities and girlfriends is because he’s avoiding being at home

•One day he doesn’t come to school and the whole school starts gossiping about what could’ve happened “Casey never misses a day? What the hell happened to him??”

•It’s not until the day after when the school is flooded with “Did you hear? Casey’s mom killed his dad!”

•He eventually comes back to school but transfers shortly after. The rumors about him won’t end and he needs a fresh start

•It used to be “Matt’s gonna be President one day” but then it becomes “shit, Matt’s gonna be the next killer like his ma!”

•Joining the Fire Academy, meeting Darden, Severide and eventually Boden is what saves his life


	6. Burzek with a baby

•It’s been years since the miscarriage and Burzek us finally, truly happy

•Living together, working together, everything is going great as it should be because they deserve the world!!!

•Adam reproposed, they had a small and cute wedding. It’s great!

•Anyways, they decide after a lot of discussion to start trying for a baby! And eventually sooner than they thought it would happen, the test comes back positive 🥰

• Kim goes to work at the 911 call center, she takes all the precautions and 9 months later delivers a very healthy baby boy!

• The parents are thrilled as all of Intelligence, 51 and Med cram into to the hospital room anxiously awaiting their turn to hold Baby Boy Ruzek

• When they’re allowed to go home, uh, Adams a bit of mess and Kim really has to keep him together

• Adams a fantastic father no doubt, but he’s worried about everything

• “Am I swaddling him too tight? Is this too hot? Too cold? Is the diaper on backwards? Am I feeding him too much? Too little? He’s whining when I hold him, he obviously doesn’t like me right?” like... the man is a mess okay

• Thankfully for him, he married the best woman in the world and she’s his rock. Constantly reminding him that if he sticks to his instincts like he does on the job then he’ll be just fine!

• Kim is the most attentive mother in the world, she almost didn’t get to have this life so she’s not taking a second of it for granted

• Adam is beyond grateful to have married such a incredible woman, even if took a while to get to where they are now

• Cause when they’ve had a bad day at work, all it takes is to go grab their little “Alvin Robert Ruzek” and cuddle up with him on the couch to make the couples day completely better 💕


	7. Stella and Kelly as everyone's favorite Aunt and Uncle

**Summary for the Chapter:**

> harapecosu asked: "Do you have any headcanons on Stellaride?? I feel like they’re the cool wine aunt and uncle in OneChicago"

•Cool wine Aunt and Uncle is such a vibe tbh

•As much as I’d die for them to have kids, I’m not completely sure if they ever will and that’s okay!

•Cause you know what that means? They get to be the aunt and uncle all the firehouse babies can rely on!

•Annabelle Hermann is experiencing her first heartbreak? She goes to Auntie Stella to cry on her shoulder

•BabyBoy Casey is quarterback on his high school football team? Stellaride are always in the stands. Sylvie and Matt have to yell at them to calm down saying “you two are more obsessed than we are and he’s our actual son!”

•Cruz and Chloe's daughter is having a hard time with a math test? Kelly sits down with her and tries his hardest to help (Stella steps in when she realizes Kelly doesn’t know shit about algebra)

•Lee Henry eventually ends up in jail (he has that’s energy for some reason) he calls Kelly, no way in hell he’d call his parents

•That leads to a argument though “If Uncle Kelly can end up jail and not get yelled at for it, then why are you yelling at me?”

•In the end, all the firehouse babies love them endlessly. Knowing when they’re parents won’t have they backs, Uncle Kelly and Auntie Stella always will! 💕💕💕


	8. Burzek Adopts

•After the miscarriage, things were obviously very rocky, those things can either make or break a couple. Thankfully it made the couple stronger

•It was hard getting Kim to open up after it but Adam is persistent and made is way back into Kim’s life/heart

•It takes a lot of coffee dates, a lot of reassurance that he won’t leave but eventually Kim believes that Adam doesn’t blame her for what happened and that he truly loves her

•After awhile, they’re happy again. It takes even more time, but eventually they decide to move into a new apartment together

•Deciding not to move into one another apartments and instead get a fresh start in a complete new place

•Then one day, Kim meets a little girl who is about to go into foster care and she can’t bear the thought of that

•So Adam and Kim decided to foster her, after while they get to adopt

•It really wasn’t a question of “if” they were going adopt, it was more like “when”

•Since they were already engaged once and already living together, it was no question if they were going to get married.

•So they have a small wedding with Intelligence so they can fill out the forms properly

•When they’re working long cases and the nanny can’t help, Cindy Herrmann and Donna Boden are the best babysitters as they are very experienced mothers

•It’s a lot work for the family. Both being in the most elite unit in the CPD while married and raising a child together but they wouldn’t trade it for the world

•Finally after so many years, after a broken engagement, a miscarriage and so many ups and downs to last a life time they are officially happy. That little girl was completely worth all the years of heartache 💕


	9. Hailey Upton and Stella Kidd being best friends

• They met for the first time at Molly’s when Hailey was only working with Intelligence, not yet assigned there

• But Stella knew she one day would be, Hailey has a air of importance and badassery about her

• There was no way she wouldn’t get to be with the most elite unit in the CPD

• After that night, Hailey loves telling Stella about Jay

• Like the way Jay is hesitant to let Hailey in but Stella reassures her that “I’ve known Jay for a while, he’ll open up eventually. Trust me.”

• Whenever Hailey is having trouble getting through to Jay, Stella is the one she go to complain too

• When Kelly and Stella's relationship is on the rocks, Hailey already has the wine poured when Stella shows up at her apartment

• They can’t always hang out, Stella works 24s and you never know when a case is going to come in for Hailey but when they get together, if neither of them are sad, it gets wild

• These ladies love to get loose sometimes, so they go to the coolest clubs when they need a break from Molly’s

• Once Jay and Hailey get together, once Stella and Kelly are finally solid, clubbing happens left more often. They enjoy double dates with their men much more

• The girls know how alike their guys are and wish they would lean on each other more so they kinda force it with is great for all 4 of them

• Eventually they get to be bridesmaids in each other’s wedding and they smile wildly at how far they’ve come ☺️


	10. Upstead and Stellaride Double Date

• They start going on double dates after Stella suggests it to Hailey one day while they’re all at Molly’s one night

• Jay and Kelly are hesitant purely because “we hang out all the time anyways, what’s the difference if we do it here or somewhere else?”

• But the girls insist on going somewhere nice and finally drag their asses out of the bar

• Jay and Kelly IN SUITS!!!!

• The image of those two in suits together could end me tbh

• Hailey and Stella IN GORGEOUS DRESSES

• Stella picks a place in Garfield Park that Donna Boden recommended

• Sidenote: Donna is the one you go to for recommendations about anything and everything

• Anyways, once they get there Stella and Hailey hook arms and walk into together

• Leaving the men stunned but not completely surprised

• The girls don’t get to see each other nearly enough because of their demanding jobs so it’s understandable that they just want to gossip

• Kelly and Jay are just happy that their ladies are happy honestly

• Speaking of which Jelly (that’s what I’m calling those two unless there’s already a ship name) are excited to see each other too!

• They talk about motorcycles, compare the action they’ve seen that week

• “I rappelled out of a burning building”

• “Yeah well I got shot at”

• But it’s all out of good fun and they laugh the whole time

• They end the night with Hailey and Stella hugging so long their boyfriends have to pull them apart

• The only way the guys get them to separate is with a promise to double date again! 💕


	11. Peter Mills Comes Back to Visit 51

• When Peter Mills walked through the doors of 51 for the first time in 6 years he knew that it wouldn’t be the same as he left it

• But he didn’t expect it have changed as much as it had

• Otis’s memorial caught him off guard even though he had heard of his death and sent his condolences

• He just didn’t have time to come back whilst running his now, very successful, restaurant in NC

• He saw more new faces than he could count, new rigs and honestly it was overwhelming

• Mills was so caught up in just watching everyone on the app floor from afar he didn’t realize that Casey had come up to until he felt a hand playfully slap him on the shoulder

• “You’re back! Took ya too damn long to come and visit us!” Casey told him

• “Cmon, I’ll introduce you to the newbies”

• But not before Severide came up to welcome him back to 51 and hound him if he was ever planning on becoming a firefighter again

• (As much as Severide supported Peter, he was never not going to be upset that he lost on one of his best Squad guys)

• Mills immediately got on with Blake Gallo, telling the younger boy stories from he was also a candidate until Casey

• Ritter, despite not technically working under Casey was also excited to hear stories from back in the day and liked knowing that a humble candidate could one day make the prestigious Rescue Squad

• When Brett finally came from call with Mackey and spotted him, she ran as fast as could to tackle him into a hug having desperately missed her old partner and friend

• She rambled about all the things she’s done since she last saw him, posts on social media and texts just weren’t the same

• Mackey had to interrupt her at one point

• “Uh hello? What about Hallack holding us at gun point and then driving us off a bridge???”

• Mills wasn’t surprised by that like Gianna thought he would be though

• “You were held at gunpoint with Sylvie? So was I! She’s a pro at now huh?” he laughed not even phased

• Sylvie dragged him into the house to show Mills all the new photos and to of course meet the new firehouse pup Tuesday

• When they ran into Stella who had heard about Mills for years and was happy to finally meet him

• “So you heard that Brett and Casey are together now right?” Stella casually says

• “No?! When did that happen??”

• “Oh well did the boys tell you that Severide has settled down with this one?” pointing at Stella and avoiding the question not wanting to get into the mess of it all

• “Lieutenant Severide and monogamy are two things I never thought would come together...”

• Overall, Mills was happy to be back in a place that’s still, after so long, felt like home

• The people might’ve gone through a lot, they may have lost from friends along the way and gained a whole lost more

• But 51 will always be the same 51 if Boden, Severide and Casey had anything to do with it 💖


	12. The Three Intelligence Guys Taking Care Of A Baby

•They rest of the team (Hailey, Kim and Voight) are out on a special operation leaving the guys by themselves

•When suddenly a baby is left at the district (police stations are safe havens)

•Everyone else is too busy to wait with the baby until DCFS gets there so Trudy assigns the baby to the guys

•Trudy doesn’t have much confidence but figures “what’s the worse they can do?”

•She honestly should’ve thought that one out better

•Cause when she gets a break and goes upstairs to check on them, she finds the following:

•Kevin is crying the corner because every time he went near the kid, it cried “Vanessa and Jorden liked me at the age, why doesn’t this one like me??? 😭”

•Adam is standing in the fridge questioning what he could give the newborn “Coffee creamer is the same as milk right?!”

•Jay, the oldest and most experienced of the three, is changing a diaper on Voights desk “There’s no way in hell I’m changing it on mine! Besides, Voights given me enough shit over the years. What he doesn’t know won’t hurt him 😏”

•Instead of helping, Trudy shakes her head and walks back downstairs. Too done with the trio to even care tbh 😅

•Finally, the other three come back. When Voight sees what a mess the three have made to his usually clean and tidy office, he’s ready to kill them all

•Until Hailey and Kim remind him maybe murder isn’t the best idea when a baby is in the room?

•Thankfully for all 7 of them the social worker comes right on time and the three men leave work that day faster than they ever have. All ready to go drink the mess of the day away swearing “a kid might be harder to handle than a criminal” 😂


End file.
